Actuators, such as wrap spring clutches, are used in various fields to transmit power from a first rotating drive element (input) to a second driven element (output). An intervening helical spring is wrapped around the first and second elements. When rotated in a first direction (i.e., when rotated by the first drive element) the helical coils of the spring compress around the first drive element and grasp the first drive element thereby engaging the first and second elements. Continued rotation in the first direction of the first element and the helical spring correspondingly rotates the second element. Interruption of the rotation of the first element or rotation in an opposed direction of by either of the first or second elements allows the helical spring to relax from the first and second elements and thereby disengages the first element from the second element. Similarly, braking of the spring rotation from rotation with the first and second elements allows the spring to relax and expand relative to its engaged configuration thereby disengaging the first and second elements.